Actuators such as hydraulic valves used in vehicles in anti-lock braking systems (ABS), traction control systems, stability control systems, and other systems typically use electrically-controlled sliding rods to selectively permit or prevent fluid flow through the actuator under particular circumstances, as required for the application.
Many such actuators have three ports, with the valve being controlled to establish fluid communication through any two of the ports as dictated by the operational circumstances. Typically, the ports are referred to as the supply, control, and exhaust ports. Such valves can be used to provide actuation hydraulic pressure to other components in the control system by moving the valve to establish fluid communication between the supply and control ports. The actuation pressure subsequently can be relieved by moving the valve to establish fluid communication between the supply and exhaust ports.
The present invention recognizes that three port actuation valves usually require the use of many components that must move precisely relative to each other with small tolerances. This burdens both manufacturing and assembly costs, and leads to valves that can be complex to make. The present invention further  recognizes that it would be desirable to provide a linear actuator valve that uses a reduced number of components compared to existing valves, that facilitates alignment of components that must cooperate with each other, and that are simpler to assemble than existing valves.